Azure Virtual Machine Scale Sets (VMSS) with a Managed Image or Shared Image Gallery version.

1. Integrate with Azure Load Balancer or Application Gateway and health probes.

2. Configure autoscale rules (CPU, memory via guest metrics, custom metrics) & upgrade policy (rolling/automatic).

Types of VMSS

1. Uniform Orchestration Mode

* All instances are identical.

* Managed as a single unit (great for stateless web apps).

* managed scale set && metrix

* disered state

* image upgrde

* group of instance

* front-end appications

2. Flexible Orchestration Mode

* Can mix VM sizes and configurations.

* Ideal for microservices or stateful apps.

* different sizes

* backend services like databases

* autopatch os

VMSS

1. image or custumize image

2. loadblancer

* network loadblancer

* application gateway loadblancer

3. vmss

4. DNS

Task:

1. create vm and install apache2

2. create image with name apache-web-server & stress

Tomcat appache installation guide:

3. create vmss

test VMSS by execute below cmds

#!/bin/bash

sudo apt update && sudo apt install stress -y

while true; do

  stress --cpu 8 --io 4 --vm 2 --vm-bytes 128M --timeout 60s -v

  sleep 30s

done